This invention relates to a steam iron with a variable steam control assembly primarily intended for domestic use, although the invention is not necessarily so limited.
Steam irons often are provided with mechanisms for changing the rates at which steam exits from steam outlet ports in the sole plates. There are occasions during which steam irons are used when no steam is desired and other occasions during which a specific rate of steam production is desired. The rate varies with the fabric being ironed and with the preferences of the person using a steam iron.
Steam is usually produced in steam irons by dispensing small quantities of water from a water reservoir through a restricted orifice into a steam chamber formed by the top surface of the sole plate and a cover plate which covers and is sealed to a portion of the sole plate. In a domestic iron, typical steam production rates are on the order of 1 to 15 grams of steam per minute. Since small quantities of water are used to produce steam within the typical range of flow rates, small differences in the size of the orifice can make substantial differences in the steam flow rates. A substantial number of cooperating parts is typically required to achieve reliable adjustments to the steam production rates in prior iron constructions. The cost of the steam production control mechanism adds significantly to the overall cost of a steam iron.
A primary object of the present invention is to provide a steam iron having a variable steam control which is inexpensive yet rugged and reliable. A steam iron in accordance with this invention comprises a sole plate, a steam chamber having an upper surface portion with a water inlet opening, a water reservoir having a bottom surface portion with a water outlet opening, and a valve assembly for directing controlled quantities of water from the reservoir into the steam chamber. The valve assembly includes a valve port member at the bottom of the water reservoir. The valve port member, which preferably comprises matrix of flexible, resilient material, such as silicon rubber, has a bore through which water from the reservoir is dispensed into the steam chamber. In addition, the valve port member has a hollow bypass conduit including an upper open end that opens to one side of the bore and a lower open end that opens along an inside wall of the bore.
The valve assembly further includes a valve element extending into the bore, and rotatable about the axis of the bore, that prevents water from flowing through the bore except for water that passes through the bypass conduit into the bore. The valve element includes a first barrier that can, by rotation of the valve element, confront and cover the open lower end of the bypass conduit to prevent water from exiting from the bypass conduit into the bore. To provide varying amounts of water passing through the bore, the valve element can be rotated to position a second, variable barrier in confronting relation to the lower end of the bypass conduit. The second barrier partly uncovers the open lower end of the bypass conduit to permit a controlled dispensing of water from the water reservoir into the steam chamber. The second barrier terminates in a third barrier which, when confronting the bypass conduit, substantially reduces the amount of water exiting from the water reservoir. A cavity is formed between the first and the third barrier which opens the bypass conduit to the extent that the steam chamber can be flooded for purging the valve assembly.
Other objects, advantages and features of this invention will become apparent from the following description and the drawings.